This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The available data strongly suggest that the causes of psychiatric illnesses are complex, and that the risk of suffering from depression, schizophrenia, anxiety disorder and other psychiatric diseases is influenced by genetic inheritance, nongenetic biological factors and external environmental factors such as social stress. In addition, it is clear that monoamine neurotransmitters (serotonin, dopamine and norepinephrine) are related to the onset and treatment of depression, anxiety disorders and other psychopathologies. Despite the evidence for genetic influences on psychiatric disorders, on levels of monoamine neurotransmitters, and on normal variation in temperament related to disease, the specific genes that affect these traits are not well known. Whole genome scanning using linkage analysis in multi-generation pedigrees is a powerful method for locating functional genes that influence complex traits such as these. Unfortunately, for several reasons, this approach cannot be used with human families to locate genes that influence cerebrospinal fluid (CSF) levels of monoamines, or to investigate normal variation in behavior. In this project, we are conducting a whole genome linkage scan in a nonhuman primate model (baboons, Papio hamadryas). We are searching for genes that influence CSF levels of monoamine metabolites (5-HIAA, HVA and MHPG) and also investigating individual variation in temperament by subjecting each baboon to a behavioral challenge involving response to novel objects. All study animals will have already been genotyped for a linkage map consisting of 350 human microsatellite loci, with 7 cM resolution. We will also use gene expression array methods to assess the molecular effects of identified QTL loci in prefrontal cortex. Preliminary results from about 300 baboons indicate that all three monoamine metabolites and several behavioral responses to challenge are strongly heritable.